Oregon's public health laboratory had confirmed 464 cases of the virus in 19 counties since it first appeared in April. Three cases have been confirmed in Jackson County. Multnomah County, which includes Portland, has the largest number of cases, with 117, followed by Marion County, with 95. No cases have been confirmed in Josephine, Coos or Curry counties.

Data compiled by the state Department of Human Services indicates the median age of Oregon cases is 17 years. The median means there are as many cases under the age of 17 as over the age of 17. Forty-seven people have been hospitalized, and five people have died, including one child and four adults.

Nationally, there have been more than 43,000 confirmed and probable cases of the virus and 302 deaths have been attributed to it. Health officials estimate that ordinary seasonal influenza kills more than 30,000 Americans every year.

Shames said health officials expect the H1N1 virus to return next fall, during flu season, and it could be more infectious than other viruses because it is a new strain, and humans have developed no immunity to it. The virus is also likely to infect more young people, and some of them will most likely get sicker than they would from ordinary influenza.

Shames noted that Oregon's summer is flu season in the Southern Hemisphere, and public health officials have been watching the virus' behavior there. So far, it has not been especially severe, he said.

Shames encouraged people to spend some time now thinking about how they would organize their daily affairs if they, or their children become seriously ill with the virus in the fall.